The Ministry of Home Safety issued advice on how to put on a gas mask :
Hold your breath
Hold mask in front of face with thumbs inside straps
Thrust chin well forward into mask, pull straps over head as far as they will go
Run finger round face piece taking care head straps are not twisted.
If out of doors people were advised to turn up their jacket collar to stop gas drifting down their necks and to put on gloves or put hands in pockets to stop open skin being hit b gas.